Despite harsh commentary from critics suggesting the painting made her look much older, Emsley tells The Washington Post, "I wanted to do something that would convey her true self, her natural self as she, herself, wanted … something that conveys something of her sense of warmth."

Emsley also revealed that has an alternative version of the portrait on his studio wall in which Kate, 31, "appears bright-eyed and young, refreshed, even playful," according to the Post – but refused to allow it to be photographed. As for the negative feedback his now-famous portrait has received, the artist brushes it off.

"Critics have a job to do," he said. "I understand that. It's not just to criticize. They're trying to interpret art for the public. That's fine. I understand why they do it, but I'm not particularly interested. I honestly wouldn't really take their opinions too seriously."

That said, when putting the piece together, he "had to consider very much the National Portrait Gallery requirements, and then my own requirements as an artist."

"I found her to be remarkable," he said. "She really does have a genuine, spontaneous warmth about her. I also found her to be very perceptive … She was interested and had interesting things to say. But the main thing I would say about her is … She is someone who makes you feel very relaxed."